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GIMA MSc. Thesis Report Thierry van der Hoeven (6529380) Assessment of Land cover and forest loss in prime Chimpanzee habitat in the Boé of Guinea-Bissau, West-Africa Final thesis report Thierry van der Hoeven August 14th, 2020 Master Thesis submitted to the Faculty of Geosciences of Utrecht University in fulfilment of the requirements of the thesis module of the Master’s program Geographical Information Management and Applications. In co-operation with the Chimbo Foundation. Specialization: Remote sensing 1 GIMA MSc. Thesis Report Thierry van der Hoeven (6529380) Abstract The Boé is a unique nature reserve in the southeastern border region of Guinea-Bissau that is home to a relatively large chimpanzee population. However, nowadays there are a number of phenomena threatening this nature. One of these phenomena is the emergence of cashew plantations. One of the focusses of this research is on this problem. However, it is difficult to distinguish cashew plantations from gallery and dry forests with remote sensing data with medium resolution. Furthermore, it is quite difficult to collect representative samples in the study area because there are few resources available and it is a very diverse and fragmented area in terms of landscape. The research aim of this study has been to identify land use trends with an emphasis on deforestation in the last 20 years and specifically in the last 4 years in the Boé area. To achieve this, samples were collected during a fieldwork campaign of four months. During this fieldwork campaign, different land cover types were sampled throughout the Boé area with an emphasis on cashew plantations and forests. After all the samples were collected, several machine learning algorithms (MLA’s) were tested to see which one provided the most representative land cover classification of the Boé area. The accuracy of the classifications turned out to be reasonably well, with an average overall accuracy of about 70% and user's accuracies of around 80 and 90% were achieved, especially for the cashew plantations and gallery forests. A change detection analysis has revealed that 70 ha of gallery forest has been lost in the Boé area between 2016 and 2020 and that the total area of cashew plantations has increased in this same period. In addition, an explorative assessment of two different forest monitoring methods was conducted to see whether deforestation could also be mapped for a longer period of time (between 2001 and 2020). The first assessment of the proven Hansen dataset resulted in some striking results. This is because the dataset showed that until 2013 not much deforestation had occurred but after 2013 but from that year on, the extent of forest loss increased rapidly in the Boé area. However, it has also shown that the extent of forest loss in the Boé area was less than in some other areas in Guinea-Bissau and in the neighboring country of Guinea. The second assessment, the BFAST monitoring method has observed a lot of forest disturbance events in the Boé area. Because all of the conducted analysis have measured forest loss, it can be concluded that the habitat of the Chimpanzees in the Boé area is decreasing, although not as much as in other surrounding areas. 2 GIMA MSc. Thesis Report Thierry van der Hoeven (6529380) Preface and acknowledgements Before you lies the GIMA MSc. thesis report "Assessment of Land cover and forest loss in prime Chimpanzee habitat in the Boé of Guinea-Bissau, West-Africa". The main aim of this thesis report is to identify spatiotemporal changes in land cover in the Boé in Guinea-Bissau, with a special focus on forest loss. Furthermore, it tried to assess whether different forest monitoring systems can be used to monitor forest loss in a fragmented landscape like the Boé over a longer period of time This thesis report has been written as part of the graduation of the master programme Geographical Information Management & Applications and was conducted in the period September 2019 until August 2020. As I was looking for a subject for the master thesis, I liked to do practical fieldwork combined with remote sensing. The WUR and the Chimbo Foundation provided me with the opportunity to accomplish both those things and also allowed me to go abroad and to contribute to the conservation of the unique environment of the Boé. Moreover, this research allowed me to develop my skills in remote sensing, which was relatively unknown for me, and to work with new program languages. I would like to thank my supervisors René Henkens and Ron van Lammeren and the founders of Chimbo, Annemarie Goedmakers and Piet Wit, for their guidance and support during this process and for all their feedback which led to the completion of this thesis. I would also like to thank all the other members of the Chimbo team and in particular Anouk Puijk and my guides Sakamoussa and Djei, who guided me throughout the Boé and without whose support I would not have been able to conduct the fieldwork. In addition, I would like to thank the local population of Belí and my special gratitude goes to Suleymane Diallo and his family, for the Fulani lessons, all the nice things that they have done for me and for making me feel at home during my period in Guinea-Bissau. Thierry van der Hoeven Amsterdam, October 2020 3 GIMA MSc. Thesis Report Thierry van der Hoeven (6529380) Table of Contents 1. Introduction ......................................................................................................................................................................... 11 1.1 Boé as valuable nature region ...................................................................................................................................... 11 1.1.1 Chimpanzees ........................................................................................................................................................ 11 1.1.2 Other endangered mammals and animals ........................................................................................................... 12 1.1.3 Sacred forests ....................................................................................................................................................... 12 1.1.4 Importance of land cover data for the assessment of land management practices ............................................ 12 1.2 Background & Context .................................................................................................................................................. 14 1.2.1 Guinea-Bissau ....................................................................................................................................................... 14 1.2.2 Population ............................................................................................................................................................ 14 1.2.3 Climate and soil characteristics ............................................................................................................................ 14 1.2.4 IBAP and the system of national protected areas ................................................................................................ 15 1.2.5 Chimbo Foundation .............................................................................................................................................. 16 1.3 Problem Definition ....................................................................................................................................................... 17 1.3.1 Threats to the habitat of Chimpanzees in the Boé (environmental challenges) .................................................. 17 1.3.2 Scientific challenges ............................................................................................................................................. 18 1.3.3 Importance of this thesis research for land management practices in the Boé ................................................... 18 1.4 Research Objectives ..................................................................................................................................................... 19 1.4.1 Sub-objective 1: create extensive classified base maps of the land cover in 2016 and 2020 .............................. 19 1.4.2 Sub objective 2: explore the feasibility of a multi temporal monitoring approach for the Boé ........................... 20 1.5 General research approach .......................................................................................................................................... 21 1.6 Research Scope and Possible Limitations ..................................................................................................................... 22 1.7 Reading guide ............................................................................................................................................................... 23 2. Review ................................................................................................................................................................................. 24 2.1 Using remote sensing in land use/land cover studies................................................................................................... 24 2.1.1 First satellite imaging ........................................................................................................................................... 24 2.1.2 Algorithm-based approaches ..............................................................................................................................